1. Field of the Invention
The present invention relates to the domain of lighting engineering, the element base of microelectronics, electronic and electromagnetic materials science, including vacuum microelectronics, X-ray optics, luminescence, including cathodoluminescence, photoluminescence and electroluminescence, specifically, to the luminescent screen technology used in field emission displays, cathode-ray tubes, light sources, X-ray electronic-optical transducers as well as optical dosimeters, etc.
2. Description of the Related Technology
The problem of luminescence realization and effective solid-state light source creation has been dealt with for 60 years already. In the classical case these purposes are accomplished with the use of phosphor powders. At the present time however there are several device designs proposed for these purposes that significantly outperform the above-mentioned classical solutions. See RF Patent No. 2144236, entitled “Cathodoluminescence Screen,” dated Jan. 10, 2000; RF Patent No. 2127465, entitled, “Method for Fabrication of Columnar-Structure Luminescence Screens,” dated Mar. 10, 1999; RF Patent No. 2214073, entitled “White Light Source,” dated Oct. 10, 2003; and WO 99/22394, entitled “Cathodoluminescent Screen with a Columnar Structure, and the Method for its Preparation,” dated May 6, 1999, all of which are hereby incorporated by reference in their entirety. This is achieved by creating light-guiding structures from the material of the phosphor itself. Nevertheless they cannot be considered as fully refined designs.
In the proposed embodiments of the prior art, the lateral surface may be included into the process of phosphor material activation for emission generation. FIGS. 1a and 1b represent columnar structures in cross-section from the prior. The numerals represent as follows: 1—transparent substrate, 2—columns of material converting energy of particles entering thereinto into electromagnetic radiation quanta, 3—flux of particles falling onto columnar structure, 4—lateral surface of columns, 5a, b—flux of quanta generated in column material as well as particles entering thereinto, 6—intercolumnar space, 7—material impermeable to particles propagating in column material. In FIG. 1a, the intercolumnar space 6 is unfilled, where is FIG. 1b, the intermediate space filled. FIGS. 1a and 1b schematically represent a process of penetration of falling particle flux into columnar structure material, propagation and reflection of emission generated thereby.
While the prior art enhances the phosphor efficiency, i.e. a portion of excitatory particles entering at an angle into the clearance between columns 6 also takes part in the phosphor activation, there are many drawbacks. For example, it is impossible to use in full measure the advantage of the light-guiding columnar screen concept that essentially consists in the total internal reflection of generated emission. Such a structure operates practically as a conventional phosphor. The particle flux 3 falling onto the lateral surface 4 and propagating 5a (and generating emission in the phosphor material) in the material of such phosphor, penetrates 5b the column boundaries in a transverse direction and undergoes multiple refraction at the adjacent column boundary. If, as is proposed by the prior art, the space between the material grains is filled with a reflecting material 7 (see FIG. 1b), the particle flux 3 falling at angle α into the intercolumnar clearance will not participate in the processes of emission activation in the phosphor material.